Pivoted double hung window



y 1955 w. E. GENCY El AL PIVOTED DOUBLE HUNG WINDOW 3 Sheets-Sheet 1 Filed Jan. 21, 1952 FIG. I.

FIG.3.

INVENTOR. WILLIAM E. GENCY ARTHu M. STARCIA BY A TTUENE Yf GENCY w. E. GENCY El AL 2,707,312

PIVOTED DOUBLE HUNG WINDOW 3 Sheets-Sheet 2;

IV V EN TOR.

WILLIAM YARTHUR M. STARQA B -m xlm wu (USA May 3, 1955 Filed Jan. 21, 1952 z I N A 0 May 3, 1955 w. E. GENCY ET AL PIVOTED DOUBLE HUNG wmnow 3 Sheets-Sheet 3 Filed Jan. 21, 1952 INVENTOR. WILLIAM E GENCY ATTOIZA/Eyj Unite Pivo'rso pounce HUNG wiNnow Application January 21, 1952 Serial No. 267,410

12 flaunts. (Cl. 20-49) This invention relates to window constructions. More particularly the invention pertains to improvements in windows of the sliding sash type wherein the sash, mounted to slide vertically, also is pivotally connected near its lower edge so that it can be turned inwardly about a horizontal axis.

It has been recognized previously that a window sash which could slide and which also coud be turned in wardly would have desirable advantages over a sash which is mounted only for sliding movement, or only for turning movement. A sliding sash is desirable because it permits an unobstructed opening of variable size without projection of the sash into the room or exteriorly of the building Wall. Modern sash balances are small in size and inconspicuous, and they permit ready adjustment of vertically sliding sash to any desired position. However, in windows having sliding sashes there is no way of controlling the direction of movement of the air through the opened window except by providing separate deflectors, and it is dangerous and practically impossible to clean the outsides of the window except from the outside. Previously it has been proposed to make windows in which the sashes are free to slide vertically, and also are pivotally mounted, but the prior constructions have been unsatisfactory or defective in construction or in operation, or have been prohibitively expensive to manufacture and install, or have been impractical for other reasons, and none of them ever has come into general or extensive use.

It is an object of the present invention to provide an improved window in which the sash can slide vertically and also can be turned inwardly about a horizontal axis located adjacent the lower edge of the sash. Another object of the invention is to provide a double hung win dow in which each sash is free to slide vertically and also can be turned inwardly about a horizotal pivotal axis. Still another object is to provide a window in which the sash can be turned about a horizontal axis to a substantially horizontal position for purposes of cleaning, and in which the sash can be easily and quickly adjusted to, and held in, any one of a number of tilted positions intermediate the vertical and the horizontal positions for purposes of ventilation. A further object of the invention is to provide mechanism which will permit a sliding window sash to be turned inwardly about a horizontal axis, and which can be installed in existing double hung windows, as well as in new Windows, withtates Patent ell) out substantial modification of the conventional sliding ice purposes of illustration and description is shown in the accompanying drawings, wherein:

Figure 1 is a front view of a double hung window taken from the inside looking out;

Figure 2 is a horizontal section, to larger scale than Figure 1, through one side edge of the upper sash and the adjacent portion of the window frame taken substantially on the line 2-2 of Figure 1;

Figure 3 is a similar view through one side edge of the lower sash and the adjacent portion of the frame taken substantially on the line 33 of Figure 1;

Figure 4 is a vertical section through the window, nor mal to the plane of the window, showing both sashes tilted inwardly about their pivotal axes;

Figure 5 is a perspective view showing a detail of the connection of the sash balance to a sash;

Figure 6 is a vertical section, normal to the plane of the window, through one of the slides attached to a side edge of a sash, showing the mechanism for holding the sash in a closed vertical position, and in tilted open position;

Figure 7 is a vertical section through the slide and mechanism of Figure 6 taken substantially on the line 7--)';

Figure 8 is a vertical section taken substantially on the line 8-3 of Figure 7;

Figures 9, 10, 11 and 12 are fragmentary vertical sections taken. substantially on the line 99 of Figure 7, but showing the mechanism for holdingthe sash in tilted position in dilierent positions of adjustment to disclose the operation of the mechanism; and

Figure 13 is a diagrammatic view showing how the sash is operated manually to adjust it to the desired tilted position.

Referring first to Figure 1, the window frame 15 is provided with an upper sash 16 and a lower sash 17. The construction of the frame is conventional for double hung windows except that the parting bead normally provided in each jamb for separating the upper and lower sashes is omitted. In new constructions it will not be necessary to provide channels in the jambs for parting beads. In the illustrative embodiment a wooden frame is shown, but it will be obvious that the invention can be used also in windows having metal. frames. The sashes are of the usual construction except that about half an inch is trimmed off from the edge of each. stile to. make the sashes slightly narrower than would be required for mounting them in the frame in the conventional way. The reason for trimming the sash stiles will be evident as the description proceeds.

Figures 2, 3 and 4 show the mechanism for mounting the sashes in one side of a frame-the right hand side as viewed in Figure 1. It will be understood that similar mechanism is provided at the other side of the frame and is similarly connected to the frame and to the sashes, corresponding parts being similarly numbered with the addition of a prime mark. This mechanism permits the sashes to be moved vertically, and also to be turned inwardly about horizontal axes adjacent the lower edges of the sashes.

Referring to Figures 14, secured to the jamb 18 of the window frame, between the inner head 19 and the outer head 20, and to the opposite jamb, are frame channel members providing two pairs of opposed runways extending the full height of the frame. Conveniently these vertical runways are formed by an upper frame channel member 21 which is substantially coextensive with the edge of the upper sash when in its raised position, and two parallel lower frame channel members 22 and 23 which are generally G-shaped in transverse section and are substantially coextensive with the side edge of the lower sash when it is in lowered position. The frame channel members are made of metal and their conformations are such that they can be rolled readily from sheet metal, for example zinc, aluminum, steel, or other suitable metal. ,The overall dimensions of the parallel lower frame channel members are similar to the overall dimensions of the upper frame channel member. The upper frame channel member and the parallel lower frame channel members are arranged in end to end relation and provide continuous parallel runways at each side of the frame for sash slides. Conveniently the frame channel members will be secured to the jamb of the frame by nails or screws 24.

Mounted in the runway provided by the lower frame channel member 22 and the aligned channel of the upper frame channel member 21 is a hollow slide 25 which is coextensive with the stile of the lower sash 17. Mounted in the parallel runway is a hollow slide 26 which is coextensive with the stile of the upper sash 16. As can be seen in Figures 2 and 3, the slides 25 and 26 are formed with longitudinal flanges 27 and 28, respectively, which engage reentrant channels in the runways to prevent trans-- verse movement of the slides relative to the frame channel members, while permitting free movement of the slides vertically in the runways.

Each of the slides 25, 26 is provided, adjacent the stile of the associated sash, with a longitudinal slot facing toward the inside of the window, the purpose of which will appear as the description proceeds. In the slide 25 this slot is located at the corner of the slide diagonally opposite the longitudinal flange 27. In the slide 26 the slot is located at the adjacent corner on the narrower edge of the slide. As can be seen in Figure 2, the slide 26 preferably is formed also with a longitudinal flange 29, parallel to the plane of the window and diagonally opposite the flange 28, against which the stile of the upper sash lies when the sash is in its closed vertical position. The purpose of the flange 29 is to serve as a stop for the upper sash when it is turned from tilted position back to vertical position, and also to limit passage of air between the edge of the sash and the slide 26. The slides 25 and 26 may be rolled from sheet metal.

The lower sash 17 is pivotally connected to the slide 25 adjacent the lower edge of the sash. In order that the lower sash may be tilted inwardly without first being raised to clear the top of the sill, the pivotal axis preferably is spaced a shortdistance above the top of the sill and a short distance on the inner side of the sash. This is shown in Figures 1-4, where a hinge plate 30 secured to the lower end of the slide 25 is connected by a hinge pin 31 to a hinge plate 32 secured on the side edge of the sash at the lower end of the stile. The lower sash can be turned inwardly about the pivotal axis through the aligned hinge pins 31, 31. Y

Secured on the side edge of the lower sash stile, and substantially coextensive therewith, is a channel-shaped member 33. This channel-shaped member conveniently is secured to the stile by nails or screws extending through the flanges thereof into the stile. As can best be seen in Figure 3, the channel-shaped member 33 is provided with a longitudinal lip or flange 34 which is parallel to the web of the channel-shaped member and spaced a short distance laterally therefrom. This lip 34 engages the inwardly facing longitudinal slot in the slide 25 when the lower sash is turned to its closed vertical position. Preferably the lip 34 engages the side walls of the slot with a fit which prevents substantial passage of air between the channel-shaped member 33 and the slide 25, but which will not interfere with the free turning of the sash about its pivotal axis when it is desired to tilt the sash inwardly. The lower end of the lip 34 terminates at the top of the hinge plate 32, so as to permit turning the sash inwardly. The channel-shaped member 33 preferably is rolled from sheet metal, and for convenience in installation the hinge plate 32 can be permanently secured thereto, as by welding or riveting.

Pivotally connected to the side edge of the lower sash, spaced above the hinge plate 32, is one end of a link 35. In the illustrative embodiment this connection is made approximately one-third of the way up from the bottom edge of the sash, but this distance may be varied. Conveniently the connection is made by a screw or rivet to the channel-shaped member 33, or to a reinforcing plate associated therewith. In the illustrative embodiment, a screw 36 engages an internally screw-threaded collar 46 secured in the Web of the member 33.

The other end of the link 35 extends through the longitudinal slot in the slide 25 and is pivotally connected to the web of a channel-shaped runner 37 slidably mounted within the slide. Conveniently this connection is made by means of a pin 38 which is secured in the end of the link and which pivotally engages a round hole in the web of the runner. In assembling the mechanism the pin 38 will be inserted in the hole in the runner before the runner is pushed in one end of the slide, and since neither the link nor the runner is free to move laterally in the assembly, this relation of the parts will be maintained as the runner moves longitudinally within the slide.

The side wall of the slide 25 facing the side edge of the sash is provided with a transverse slot 39 to receive the collar 40 when the sash is turned to its closed vertical position. When the sash is in vertical position the link 35 will lie completely within the hollow slide 25, with the longitudinal axis of the link substantially parallel to the longitudinal axis of the slide. Figure 6 shows the runner 37 substantially at the upper limit of its range of move ment within the slide, but merely for purposes of providing a clearer disclosure of the connection of the link to the runner, the link is shown at an angular position which is different than it occupies when the mechanism is attached to a window and the runner is in the position shown.

It will be evident from the foregoing description and from inspection of Figure 4 that as the lower sash 17 is tilted inwardly about its pivotal axis, the link 35 will cause the runner 37 to move downwardly in the slide, and that as the sash is tilted back toward the vertical position the link will move the runner upwardly in the slide. By providing means for selectively locking the runner in a plurality of adjusted positions within the slide it is possible to hold the sash in a plurality of tilted positions.

The construction and operation of the mechanism for locking the lower sash 17 in closed vertical position, and of the mechanism for selectively locking the runner 37 in an adjusted position Within the hollow slide 25 when the slide is tilted, will next be described, reference being had particularly to Figures 613 of the drawings.

Secured within the upper end of the slide 25, as by screws 41, is a stop 42. Conveniently this stop is formed from a cruciform piece of sheet metal, such as steel, the vertical bar of the cross being substantially longer than the horizontal bar. The ends 43 of the horizontal bar are bent at with respect to the plane of the central portion, and when the stop is inserted telescopically into the upper end of the slide 25 the flanges formed by the bent ends 43 serve to position and hold the stop against transverse movement within the slide.

Secured to the upper end of the stop 42 is a spring pressed latch for holding the sash 17 in closed vertical position. In the illustrative embodiment the upper end 44 of the vertical bar of the cross also is bent at 90 with respect to the plane of the central portion to form a horizontal flange. The flange 44 has a hole drilled centrally therethrough to slidably receive a pin 45. The pin 45 has a head on its lower end which limits its movement upwardly through the hole in the flange 44. The pin projecting above the flange 44 is surrounded by a compression coil spring 46, and the upper end of the pin is secured, as by riveting, to a latch member 47 which is telescopically received within the upper end of the slide 25. The coil spring 46 resiliently presses the latch memher 47 upwardly until the head on the lower end of the pin 45 engages the flange 44, and when the stop 4-2 is secured in position in the slide by the screws 41, the upper end of the latch member projects slightly above the top end of the slide.

The latch member 47 conveniently is formed from sheet metal, two opposite side edges thereof being bent at 90 to provide flanges for aligning the latch member within the slide, and the upper edge being bent at 90 to provide a closure for the upper end of the slide. Projecting laterally from the latch member through an opening in the wall of the slide facing the edge of the sash stile is a catch 48. Conveniently the catch is formed integrally with the latch member as shown. When the sash 17 is in vertical position this catch 43 engages a hook d9 (Figure 4) secured to the side edge of the sash stile at its upper end to lock the sash so that it cannot be tilted inwardly. When it is desired to tilt the sash inwardly the operator merely depresses the latch member 4'7 slightly against the pressure of the coil spring 46, thus freeing the catch 4-8 from the hook 49 and permitting the sash to be turned inwardly about its pivotal axis. when the sash is returned from tilted position to vertical position, the oblique end of the hoot; 49 engages the catch 43 and presses the latch member downwardly against the pressure of the spring until the hook passes over the catch and the members lock.

Secured to the lower end of the vertical bar of the stop 42 is a guide bar 50 which extends longitudinally downwardly within the slide and along which the runner 37 can move vertically within the slide. This guide member is a notched bar rack. In the illustrative embodiment the rack 50 terminates at short distance below the trans verse slot 39 in the side wall of the slide, but the length of the rack may vary depending on the length of the link and its point of connection to the sash stile. The rack will be of sufficient length to permit turning the sash inwardly to substantially horizontal position. The rack 50 cooperates with a spring pressed check 51 mounted on the runner 37 to selectively lock the runner in adjusted position along the rack within the slide 25, so as to hold the sash in the desired tilted position.

The check 51 has secured thereto a pivot pin which extends through a transverse slot 52 in the web portion of the runner. The end of this pivot pin opposite the check is headed so as to hold the pin in the slot 52. check 51 has a limited freedom of turning movement about the axis of its pivot pin and also is free to move transversely relative to the runner within the limits imposed by the slot 52. The end of the check opposite the pivot pin is formed with a transverse lug 57 for engaging the notched edge of the rack 5t and formed on the side of the check toward the rack is a transverse car 58 which also engages the notched edge of the rack 50 and serves simultaneously as a spring stop.

The check 51 is resiliently pressed toward the notched edge of the rack 50, as by a coil spring 53 surrounding the headed stud 54 projecting from the web ofthe runner 37. One of the uncoiled ends of the spring engages the side flange of the runner opposite the rack 5t and the other uncoiled end of the spring, curved as shown in the drawings, engages the car 58 on the side of the check, thus pressing the cheek to the left, as viewed in Figures 8-12, against the notched edge of the rack.

The other side flange of the runner 37 is free to slide along the flanged back edge of the rack and is held firmly against the back edge of the rack by the spring 55, the central portion of which is looped around the headed stud 56 projecting from the web of the runner, and the curved ends of which bear resiliently against and ride along the inside of the flange at the back edge of the rack. Pressure of the runner flange against the flanged back edge of the rack acts as a brake to retard movement of the runner along the rack.

The operation of the mechanism for selectively lock- The i 5 ing ,the sash in adjusted tilted position will be described in connection with Figures 8l2, and references, herein to right or left, and to clockwise or counter-clockwise will be understood to apply to the mechanism as viewed in these figures.

When the sash 17 is in closed vertical position, the runner 37 will be at the upper limit of its range of movement within the slide 25. The pivot pin of the check 51 will be pressed toward the left end of the transverse slot 52 by the spring 53; the car 58 of the check will rest in the uppermost notch 59 of the rack 59;. and the check will be turned in a counter-clockwise direction, by reason of engagement of the car 58 with the upper edge of the notch, until the end of the check rests against the side flange of the runner 37.

When theisash is tilted inwardly from its vertical position, the link 35 moves the runner downwardly in the hollow slide 2:5, and engagement of the car 53 with the lower edge of the notch 59 first turns the check in a clockwise direction until the lug 57 engages the sloping upper edge of the second notch 60. As the runner continues to move downwardly, the ear 5'3 rides up the sloping lower edge of the notch 59, moving the pivot pin of the check to the right until the ear 58 clears the top of the tooth separating the notches 5'? and 64). Upon continued downward movement of the runner, the lug 57 engages the sloping lower end of the notch 60, substantially as shown in Figure 8, and downward move ment of the runner is halted. Without further action by the operator, the sash 17 will be held in its first tilted position.

If it is desired to tilt the sash inwardly a greater distance, this can be done merely by tilting the sash back through a small angle toward the vertical, and then again tilting the sash further away from the vertical. As the sash is tilted back toward the vertical from the position shown in Figure 8, engagement of the car 58 with the upper edge of the notch 69 causes the check to turn in a counter-clockwise direction until the end of the check rests against the side flange of the runner. As the check turns, the car 58 moves from the curved. portion of the spring 53 to the straight end portion thereof, substantially as shown in Figure 9. Upon reversal of the sash tilting movement, the runner 3'? will again move downwardly in the hollow slide 25 and the check will be held by the spring 53 in its counter-clockwise position, so that the lug 57 now clears the lower edge of the notch 60.

Continued downward movement of the runner brings the ear 58 of the check into engagement with the lower edge of the notch so, which first causes the check to turn in a clockwise direction until the lug 57 engages the edge of the rack'Sil, as shown in Figure 10, and then causes the pivot pin of the check to be moved to the right in the transverse slot 52, to the position shown in Figure 11. Downward movement of the runner will be halted when the lug 57 engages the lower edge of the third notch 61, as shown in Figure 12. In the absence of further action by the operator the sash 17 will be held in its second tilted position.

Additional notches 62 similar to 60 and 61 may be provided spaced along the edge of the rack 50 to permit adjustment of the sash to other tilted positions, and the spacing between notches can be made as desired. Upon tilting the sash inwardly it will be locked successively in open positions as determined by these notches in the rack, tilting of the sash from one open position to the next open position being made possible merely by a short reversal of the tilting movement at each locked position. This is illustrated somewhat diagrammatically in Figure 13, where the lower sash is shown by solid lines in one of its locked tilted positions. Upon tilting the sash toward the vertical through the small angle a, the check 51 is turned and held so as to permit tilting the sash inwardly through the angle b to the next locked tilted position, shown in dotted lines.

The spring 55 desirably presses the flange of the runner 37 against the flanged back edge of the rack 50 with suflicient force to retard tilting movement of the sash inwardly under its own weight, or under the pressure of the wind, and to prevent rebounding of the sash upon engagement of the lug 57 with the lower edge of a notch in the rack. Otherwise the sash, tilting inwardly under its own weight or under the wind pressure, might rebound sufiiciently to cause the check to turn far enough in a counter-clockwise direction to permit further tilting of the sash, and this operation might be repeated as successive notches of the rack were reached by the check, until the tilting movement was stopped by some other means.

Desirably, when the sash is tilted inwardly to a substantially horizontal position the runner will be locked against further downward movement within the slide so as to minimize danger of damage to the sash, and also to prevent any possibility of the runner moving completely off from the lower end of the rack. This object can be attained by providing the rack with two closely spaced, V-shaped notches 63 and 64- toward its lower end. When the runner is moved downwardly until the car 58 of the check overlies the notch 63, the spring 53 will press the pivot pin of the check to the left and the ear 58 will drop toward the bottom of the notch 63. Upon continued downward movement of the runner, engagement of the ear 58 with the lower edge of the notch 63 will cause the check to turn in a clockwise direction and will move the lug 57 into engagement with the lower edge of the notch 64, halting further downward movement of the runner. Upon slight reversal of the tilting movement of the sash, engagement of the ear with the top edge of the notch 63 will lift the lug 57 from the notch 64. However, if the sash is again tilted inwardly, engagement of the ear S8 with the lower edge of the notch 63 will once again turn the check in a clockwise direction to bring the lug 57 back into engagement with the lower edge of the notch 64. Consequently, the runner is unable to move downwardly beyond the point where the lug 57 engages the notch 64.

From the foregoing it will be evident that the sash 17 may be tilted inwardly, step by step, from a vertical position to a horizontal position merely by reversing the tilting movement slightly when the sash reaches each locked tilted position. Alternatively, the sash may be left in any one of the locked tilted positions, as desired, for purposes of ventilation. The sash may be turned from any tilted position to its closed vertical position in a single continuous movement, the car 58 of the check dropping successively into the notches of the rack and sliding up the gradually sloping upper edges thereof.

Any attempt to move the sash 17 in a vertical direction while the sash is tilted inwardly would be likely to result in uneven vertical movement of the slides in their runways at the opposite edges of the sash, with the possibility of damage to the mechanism connecting the sash to the slides. In order to obviate this danger, mechanism is provided which operates automatically, regardless of the vertical position of the slides in their run ways, when the sash is tilted inwardly from its vertical position to lock the slides against vertical movement in their runways.

Pivotally mounted on a stud secured in the stop 42 is a cam pawl 65, with which is associated a spring 66. This spring biases the pawl about its pivotal axis toward the edge of the slide 25 which faces the inner head 1% of the window frame. Located in the wall of the slide 25 opposite the pawl is an opening 67. When the sash 17 is in its closed vertical position, the runner 37 will be at the upper limit of its ran e of movement, as shown in Figures 6 and 7, and one of the side flanges of the channel-shaped runner engages the end of the pawl to hold it, against the pressure of the spring as, clear of the opening 67. As soon as the sash is tilted inwardly, the runner moves downwardly in the slide and the end cal of the pawl, no longer restrained by the flange of the runner, is pressed outwardly by the spring 66 through the opening 67 into engagement with the edge flange of the upper frame channel member 21, which is backed up by the inner head 19. Engagement of the springpressed cam with frame channel member serves to lock the slide against vertical movement. Figure 8 shows the pawl d5 extending outwardly through the opening 67 in the wall of the slide.

When the sash 17 is returned from tilted position to its vertical position the runner 37 moves upwardly in the slide, and as the runner nears the upper limit of its range of movement within the slide the runner flange engages the cam edge of the pawl to turn the pawl, against the pressure of the spring 66, back into the slide, thus freeing the slide for vertical movement in its runway. Figure 9 shows the pawl partially freed from the flange of the runner.

The upper sash 16 has mechanism connecting its side edges to the slide 2 5, and to a similar slide at the opposite edge of this sash, which corresponds in all essential respects to the mechanism which has been described in connection with the lower sash 17. One difference is that the pivotal axis of the upper sash extends through the loweredge of the sash rather than being displaced on the inner side of the sash. The upper sash can be tilted inwardly to horizontal position, or can be selectively adjusted to intermediate tilted position between the vertical and the horizontal. Obviously, the upper sash can be tilted inwardly only after the lower sash has been tilted inwardly at least part way, but otherwise either sash may be tilted independently of the other. Also, in the illustrative embodiment, the upper sash can be tilted only after it has been lowered at least slightly to permit access to the latch members which are located in the upper ends of the slides and which lock the sash in vertical position. it will be evident that the lower sash can be raised to any desired position before being tilted inwardly, and that the upper sash can be lowere as desired before being tilted inwardly.

The sash balances which permit the sashes to be adjustcd to any desired vertical position in the frame will next be described. The sash balances disclosed are of the coil spring type in which the balancing action results from turning the spring. The mechanism at one side of the window will be described and it will be understood that similar mechanism is provided at the opposite side of the window.

Located within the upper frame channel member 21- are two parallel coil springs 62?, 6%, the upper ends of which are secured against rotation and against movement longitudinally within the member 21, near the upper end thereof. Conveniently the springs are secured by nails or screws which extend through the wall of the frame channel member, and through caps secured on the upper ends of the springs, into the jamb l8. These coil springs are approximately coextensive with the frame channel member 231. Secured on the lower ends of these coil springs 68, 69 are slotted bushings which receive the twisted or spiral rods 70, 71, respectively. The lower end of the twisted rod 70 is connected by a link 72 exending outwardly through the longitudinal slot in the G-shaped lower frame channel member 22 to the lower end of the slide 25. The lower end of the twisted rod '71 is similarly connected by a link extending outwardly through the longitudinal slot in the G-shaped lower frame channel member 23 to the lower end of the slide 26.

As either sash is raised or lowered, the spiral rod connected to the sash slide will move vertically through the slotted bushing in the lower end of its associated coil spring. The coil spring will be twisted tighter as the sash is lowered, thus tending to raise the sash, and the tension in the spring will be relieved as the sash is raised. It may be desirable to limit the downward movement of the upper sash and this can be done by providing a stop 73 located in the lower frame channel member 23, near its lower end.

The invention herein disclosed may be variously modilied and embodied within the scope of the subjoined claims.

We claim:

1. In a window structure comprising a frame having a sill, side jambs and a head, and an upper sash and a lower sash mounted in the frame for sliding movement vertically past each other, in combination, frame channel members secured to the jarnbs of the frame providing two pairs of opposed sash runways extending the full height of the frame, hollow slides substantially coextensive with the stiles of the upper sash mounted in one pair of sash runways, hollow slides substantially coextensive with the stiles of the lower sash mounted in the other pair of sash runways, the slides and the frame channel members being formed with interengaging longitudinal flange portions which prevent movement of the slides transversely out of the runways while permitting vertical movement of the slides in the runways, each of said slides having a longitudinal slot facing toward the inside of the window providing access to the interior of the slide throughout its length, a runner within each slide, a guide bar secured within each slide along which the runner can move vertically within the slide, aligned pivotal connections between each of the sashes and its two slides adjacent the lower edges of the sashes, four links, each link pivotally connected at one end to one side edge of a sash at a point spaced above its pivotal connection to the corresponding slide, the other end of the link extending through the longitudinal slot in the slide and being pivotally connected within the slide to the runner therein, and means located within each slide for locking the runner in a plurality of adjusted positions along the guide bar therein when the sash is tilted inwardly about its pivotal connection.

2. A window structure according to claim 1, characterized by the fact that there is an upper frame channel member substantially coextensive with the stiles of the L upper sash which provides parallel runways for both sashes, and two parallel lower frame channel members each providing a runway for one sash aligned with the runways of the upper frame channel member, the overall dimensions of the two parallel lower frame channel members being similar to the overall dimensions of the upper frame channel member.

3. A window structure according to claim 1, characterized by the fact that the upper frame channel member includes a common enclosure for the upper ends of sash I balances for both sashes intermediate the sash runways, and by the fact that two parallel coil springs within said enclosure are secured at their upper ends against rotation and longitudinal movement, and further characterized by the fact that the lower frame channel members are G-shaped in transverse section to provide individual longitudinally slotted enclosures for the lower ends of the sash balances, and by the fact that the lower end of each slide is operatively connected to the lower end of the corresponding sash balance by a link extending through the longitudinal slot in the lower frame channel member.

4. A window structure according to claim 1, characteriZed by the fact that the longitudinal slots in the slides have lips extending toward the inside of the window parallel to the side edges of the sash stiles, and by the fact that the edges of the sash stiles are covered with channelshaped members which are substantially coextensive with the stiles and are secured thereto by fasteners through the flanges of the channel-shaped members, and in which each channel-shaped member has an integral longitudinal lip parallel to the web of the channel-shaped member and spaced a short distance laterally therefrom, said lip on the channel-shaped member projecting toward the outside of the window and being aligned with the longitudinal slot in the corresponding slide so that the edge of the lip on the slide will be engaged between the web and the lip of the channel-shaped member when the sash is in vertical position.

5. A window structure according to claim 1, characterized by the fact that each slide has an opening facing toward the adjacent bead 011 the frame, and a spring pressed cam pawl secured within the slide opposite said opening, and further characterized by the inclusion of means located within the slide to press the pawl away from the opening when the sash is in vertical position, and to release the pawl through the opening automatically as the sash is tilted inwardly about its pivotal axis at any vertical position of the sash within the frame.

6. A window structure according to claim 5, in which the spring pressed cam pawl is located in the upper end of the slide, and in which a portion of the runner within the slide engages the pawl and presses it inwardly of the slide as the sash is turned from tilted position to the vertical position.

7. A window structure according to claim 1, characterized by the fact that the means for locking the runner in adjusted position along the guide bar within the slide operates automatically as the sash is tilted inwardly, and further characterized by the inclusion of means within the slide which operates to release the locking means upon a slight tilting of the sash back toward the vertical position, so as to permit further tilting of the sash inwardly beyond one locked position to the next locked position.

8. A window structure according to claim 7, characterized by the fact that the guide bar secured within the slide is a notched bar rack having a plurality of notches, and by the further fact that secured on the runner is a spring pressed check which moves along the rack as the sash is tilted inwardly about its pivotal axis and engaged the notches therein successively, locking the sash against further tilting movement as each notch is engaged, until the locking means is released.

9. A window structure according to claim 8, including means actuated automatically upon a slight reverse tilting of the sash after the check has engaged a notch in the rack to lift the check and hold it in lifted position to permit the check to pass over the notch upon further tilting of the sash inwardly.

10. A window structure according to claim 9, including means actuated automatically as the check passes over the notch to release the check holding means, so that the check will engage the next notch on the rack as the sash is tilted further inwardly.

11. A window structure according to claim 10, including brake means for resiliently pressing the runner against an unnotched longitudinal edge of the rack to retard movement of the runner along the rack.

12. A window structure according to claim 1, characterized by the inclusion of brake means associated with the runner and the guide bar for retarding movement of the runner within its slide.

References Cited in the file of this patent UNITED STATES PATENTS 1,658,317 Wight Feb. 7, 1928 1,886,968 Monsch et al. Nov. 8, 1932 2,017,652 Carl Oct. 15, 1935 2,126,177 Dennis Aug. 9, 1938 2,305,275 Pyle et a1 Dec. 15, 1942 

